What are some effective ways to travel on a budget without sacrificing comfort?

I’m planning a week-long trip across Europe on a tight budget, but I really don’t want to sacrifice comfort. I’ve heard that there are ways to travel affordably while still enjoying a pleasant experience. What are some effective ways to travel on a budget without sacrificing comfort? Any tips on finding good accommodations, affordable transportation, or other budget-friendly travel strategies would be greatly appreciated!

Use budget airlines, book hostels or affordable hotels, and use public transport. Look for city passes.